Automatic safety cut-off



A. L. MILLER AUTOMATIC SAFETY CUT-OFF Filed April 30, 1923 2 Sheets-Sheet 1 Jan. s 1924.

Jan. s, 1924. 1,480,093

A. L. MILLER AUTOMATI C SAFETY GUT- OFF Filed April 50. 1923 2 Sheets-Sheet 2 Patented Jan. S, 1924,

UNITED STATES lMhMB ALBERT L. MILLER, OF JOHNSTOWN, PENNSYLVANIA.

AUTOMATIC SAFETY CUT-OFF.

Application led April 30, 1923.

To all Lv/7.0m t may Concern.

Be it known that I, ALBERT L. MILLER, a citizen of the United States, residing at Johnstown, in the county of Cambria and State of Pennsylvania, have invented certain new and useful Improvements in Automatic Safety Cut-Offs, of which the following' is a specification. i

The invention relates to a controlling valve adapted for use in a gas supply system, and particularly in the s maller pipes lo l cated adjacent a burneror other point of gas tion.

consumption. The valve which is the subject of the present invention is adapted to be automatically closed upon a reduction of pressure within the lpipe in which it is located, and is delicately balanced so as to be sensitive to much smaller variationsin pressure than the devices of this general character which have been in use heretofore.

An object of the invention, therefore, is to provide an improved safety valve ofthe character described which will automatically close upon reduction of gas pressure, and which will be automaticallylockedv in the closed position until manually released.

A. further object is to provide improved locking and lock retaining mechanism for use in connection with the valve.

Another object is to provide a substantial structure which, while sensitive to slight changes in pressure, is nevertheless capable of withstanding very large pressures.

Another object is to provide an improved form of casing for the valve mechanism.

Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings lin which Figure 1 is a central vertical -section through the valve casing, the valve andv locking mechanism being shown in eleva- Figure 2 isa top plan view of the same.

Figure 3 is a view similar to Figure 1 showing a modifica-tion.

Figure 4 is a perspective View showingv the improved lock and retaining and release mechanism therefor, these parts being the same in both embodiments ofthe invention. The reference numeral 10 denotes a valve serial no. 635,580.

casing, which is shown as comprising an up wardly and outwardly flaring portion 11 and a horizontal portion 12, the latter being provided with screw threaded end portions into which are screwed gas pipe sections `13, 14, one of which leads from a gas main, and the other to a burner. or other point of use. Extending across the valve casing isa transverse partition 15 formed with 'a valve sea-t 16.

Under normal operation the gas passes freely through the valve casing from the in'- let pipe 13 through the valve seat to the outlet pipe 14, as indicated by the arrows. When, however, the pressure in the pipe line is for any cause materially reduced itis desirable that the flow of gas to the burners be entirely cut off in order to avoid leakage of gas at the burner. To accomplish this result a safety valve 17 is provided which is automatically closed whenever the gas pressure falls below a certain point.

As shown the stem 18 of valve 17 works in a guide member 19 which is preferably threaded into the horizontal portion of the casing 11. This guide member is provided with a plurality of vertical gas passages 2() leading to a pressure chamber 21 within the flaring portion of the casing. A flexible diaphragm 22, .which may be of leather or other suitable material, closes the upper portion of the chamber 21. 4

In order to protect the diaphragm 22 in case of excessive pressure a metallic guard ring 23 is provided. This ring is preferably separated from the diaphragmby means of a spacing ring 24. Above the guard ring is secured a bracket 25 which supports the automatic locking; mechanism for the valve` stem. Covering the whole mechanis'mris a dust guard or cover 26, which is shown as outwardly flanged as at 27 and bolted to a corresponding flange 28 of thel casing 11 by z means of 'bolts 29y which serve also to secure the diaphragm 22, guard ringj23, spacing ring 24 and bracket 25..

'As `shown the valve stem 18 is provided with anv extension 30 which is 4screwed into the upper portion thereof 'and extends through the diaphragm 22. A. reinforcing assied th t plate 3l rests upon the diaphragm 22 being of suiiicient size to cover the opening in the guard ring 23. The reinforcing plate is locked in position by means of a nut 32 Which is threaded upon the stem extension.

Under normal conditionsthe mechanism yis in the position shown in fulllines, the valve 17 being raised by means of the gas pressure which acts through the. medium of the diaphragm 22, the Weight' of the lvalve and stem being preferably counterbalanced in -part by means of a Weight 33 Which is shown as adjustably mounted upon a Vstem v34 yhinged to the valve stem 16 and fulcrumed Within a bracket 3.5, lwhich ,forms an .extension ,of the stem guide 19.

When the pressure beneath the diaphragm is reduced `the valve 17 is flowered to its seat 1,56 due tothe Weight of the yvalve ,andstenr In ,order to prevent the -valve 4from ragain opening .upon a subsequent .increase of 44pressure an automatic locking mechanism is provided. This locking mechanism fis .sensitive in its operation, and serves to positively lock the .valve ,in the lowered vposition until the lock is' manually released.

,ris Vshown .the lock consists of Va Weighted locking segment 38 l.rncurused upon a shaft 3,9 journal-led inthe bracket 25. When the pressure falls vandthe valve stem 19 is in its lowered Iposition the segment 38 .assumes the .position shown in `dotted lines in Figure 1, the loclr being directly over the .top of the stemythus preventing the valve from being Opened To return the lock to inoperative position a manually actuated releasing; mechanism is provided. As shown this mechanism consistS .Gf .a plate 39 liavinpv,` ofiset portions l0j 41, bent at right angles to the piane ot the plate. Ithese ol'sets forming lears which aresuspended from the shaft 39. The portion 41 is extended to form an operating lever which is readily accessible when the dust guard or cover 26 is removed. When the locking segment has been returned to the position jshown in full linges in Figure 1 the valve stem Wil-l be at once returned to the raised position, provided the gas pressure .ivithin the system has been restored to normal. The lower end .of the plate 39 noiv 4projects below the top of the valve stem lshoi'vnin Figures 1. and 3. At the upper et the plate is provided a forwardly extending member ,412 which coacts with .the .upper arm of a bell crank 4:4, pivotally "mounted upon `the bracket 25. The 'other arm V45' of the bell era-nk forms a catch which engagesa pin 46 on the locking segment 38. The Weight of the piate 13,9 is so distributed that the plate tends to swing beyond the .vertical position aidthe lovvleredge ,of the plate rests lightly 'Op df the relie stemlfilhen the stem is lowered, therefore, the plate 39 swings in a counterclockwise direction. thus releasing the bell crank 44:, and catch 45 whereupon the locking segment 33 falls of its own Weight to the locking position. y

Preferably a spring 4:6 is provided for `the ypurpose of assisting the operation of the locking segment. As shown the spring is coiled about the ends of the sha-ft 39, o-ne end vof the spring bearing against a pin 47 on the locking segment 38.

IThe construction shown in Figure 3 is the same as that just described in connection with Figures 41 and 2 .exceptthat -diaphragm 49, spacer 50, Iguard :ring 511 and bracket `52 are screw vthreaded Within ythe upwardly fla-ring casing 53, a shoulder 154; being provided upon which .the diaphragm rests.

lt is obvious that numerous,otherchanges may be made in the details .of-construction Without ldeparting trom the spirit/of the invention.

claim:

1. An @automatic gas .cuto .mechanism compri-sing the combination with .a Avalve casing valve .seat and vertically reciprocating valve of .a stem .extending .abovesaid casing, a Weighted locking segment l,pi-voted above ythe `valve stem, means for normally retaining .said locking segment in inoperative position, said means being adapted to engage the upper portion of the valve stem in its raised position.

y2. An automatic cutoi mechanism ycomprisingin combination la pressure chamber, a diphr-agm `:located therein, a yvalve having its stemV secured to said ydiaphragm and adapted for reciprocating movement, a Weighted locking segment -pivoted above said stem, a `pivot-ed lock retaining `member adapted to normally hold said segment in inoperative position, said retainer having a portion adapted to engage the upper end ot the valve stem.

3. An automatic gas cutoi mechanism comynising in combination with a valve easing, valve seat and vertically reciprocating valve ot' a stem extending above Tsaid easing, a locking member pivoted .above the valve stem. and va catch engaging the upper end of the valve stem in its raised position for retaining the lock in inoperative posi.- tion.

4i. An automatic gas cutoff mechanism comprising in combination with a valve casing. valve seat and vertically reciproeating valve of a stem extending above said casi-ng, a. loclri-ng member pivoted above the valve Stem, and a riveted @steh yensesinsthe upper end of the valve stem in its raised posities for reif-.liaise thelok in imperative residenlill@ 5. An automatic gas cutoff mechanism position for retaining the lock in inoperacomprising in combination With a valve oastive position, and. a pivoted bell crank one ing, Valve seat and vertically reciprocating arm of which engages a portion of said 1G valve of a stem extending above said oascatch, While the other arm engages a pin o-n 5 ing, a locking member pivoted above the said looking member. valve stem, a pivoted catch engaging the In testimony whereof I affix my signature. upper end of the valve stem in its raised ALBERT L. MILLER. 

